Building material and process of making the same



I06. COMPOSITIONS,

COATING OR PLASTIC.

' Patented Mar. 18, 1941 I (ct/7 UNITED STATES LXHIIIIIIOI' PATENT OFFICE BUILDING MATERIAL AND PROCESS OF MAKING THE SAME No Drawing. Original application July 11, 1935,

Serial No. 30,942.

Divided and this application June 8, 1937, Serial No. 147,040. r? 12 Claims. (01. 106-;24IX

This invention relates to a cementitious composition for roofing and s1 mg material and to a process for making the same. The invention moreover, particularly relates to roofing and sid- 5 ing elements comprising said composition or having said composition as a facing or surfacing. This application is a division of my copending application Serial No. 30,942 filed July 11, 1935.

Portland cements or other hydraulic cements containing free lime have generally been unsatisfactory for the weather exposed surfaces of shingles in roof or siding coverings and for other building materials, particularly where the surfaces are colored other than white, because of their tendency to liberate salts forming a surface blemish of irregular areas or spots of white crystals, commonly referred to as blooming or eiilorescence. It is believed that the blemish may be due to the liberation ofcalcium salts or calcium hydroxide which migrate to the surface of the cement where they react with the carbon dioxide of the atmosphere to form a deposit of crystals of calcium carbonate. While it has been proposed to remove the affected areas by scrubbing and washing, and to some extent by other known surface treatments, the action continues to recur during aging of the cement as long as any free lime remains, unless resisted in the manner described in my Letters Patent No. 2,071,681, granted February 23, 1937. Factory treatments, while helpful, are obviously not a satisfactory solution and are, moreover, expensive. Furthermore, it is also apparent that the layman does not desire to scrub or treat the roof or sides of his building to remove the blemish when it is realized that such will recur.

It has also been proposed to make porous cement products by employing Portland cements containing free lime or to which an excess has been added, and including therewith metallic aluminum as a gas forming agent to bring about volume expansion, In order to obtain a proper reaction of the metal to effect the liberation of gas, the presence of ree lime has been considered vitally essential an I herefore only cements of that character have heretofore been used. Such proposals not only result in products that bloom upon exposure but obviously require a consideration of the free line content. Moreover, the compositions require a considerable period of curing before sufficient strength is available for use of the product.

Furthermore, shingles having a slab of slate 55 cemented to a base sheet by asphalt or the like to form the weather exposed portion thereof have been proposed, but have been unsatisfactory because of the unfavorable bond between the dense slate surface and the adhesive. Moreover, as shingles are generally laid upon steeply inclined 5 surfaces the considerable mass of the slate slabs also results in slipping between these two layers in weather exposure, under the influence of heat. Slabs of a sand-cement composition are also substantialy dense and heavy and have similar dis- 10 advantages, unless applied as a plastic and provided with some form of intermediate bond such as mineral granules anchored in the bitumen.

In accordance with the present invention it is believed that the aforesaid considerations are sub- 15 stantially avoided, if not entirely prevented.

It is among the objects of the invention:

To provide a substantially firm, light weight porous product for exposure to the weather, which is resistant to heat and the erosive and softening action of water and substantially free of surface blooming or eillorescence.

To provide an improved process for making a material of the type indicated.

To utilize the aforesaid characteristics of the composition of the invention in the provision of a roofing and siding shingle.

To treat a plastic mass comprising a high aluminate or natural cement with a levitating agent to form a light weight product containing a considerable percentage of voids,

To provide a porous cementitious product containing facial voids for the mechanical anchorage of a further plastic material.

To provide products of the aforesaid character possessing a considerable percentage of voids to provide insulation and/or sound absorbing properties.

To provide a semi-rigid shingle element including a flexible base and a non-slipping facing comprising a porous cement composition, which facing may be bulked at the butt portions to provide a heavy edge for weather exposure. I

To provide a composition adaptable to the natural formation of rough textures or to the obtaining of particular effects-such as that of stone or brick by embossing a face of the composition.

Various other objects will be apparent from the following description and claims.

In order to overcome the highly objectionable feature of blooming or eillorescence to a marked degree, I prefer to use a high alumina cement preferably carr n between o of calc um aluminates r ca cum 9. um fem es w ch when properly made as by fusion, are Elieved to be entirely free of free lime. High aluminate cements including quantities of free lime which have been substantially converted into such products as calcium carbonate in their making, and 5 natural cements are also substantially satisfactory in overcoming the objection. Such cements are substantially free or greatly resistant to blooming or efllorescence and retain their surface characteristics for long periods of time. Also the high aluminate cements obtain a high early strength and this property is also of considerable importance in a porous structure for the walls of the voids quickly gain full strength and permit use of the product shortly after forming. It is thus a feature of the invention to provide a cementitious composition containing ingredients possessing one or more of the aforementioned characteristics.

A further feature of the invention comprises the treatment of a cement of the above type by 1 reduce, ,iht weih rous or celfiil'a'r mas con an ac ual voids, an v g characteristics suitable for covering materials for interior and exterior application, for instance, walls, roofs and sides of buildings, tiles and composite structures including waterproof or fibre layers. To accomplish this, in general I incorporate with the cementitious mass which may include extending materials, suflicient liquid to accomplish its hydration and a material which reacts in the presence of these ingredients to give of! or generate a gas. Such material is preferably mixed with the dry constituents or included when the wet mix is made. Bubbles of the gas are dispersed throughout the mass during the setting reaction, causing the mass to expand considerably in volume. The action continues until the material is either exhausted or the mass has set. Obviously, the amount of expansion will be somewhat dependent upon the extent of gas generated and upon the nature of the cement composition and its ability to hold the bubbles thereof. It has been found that under certain conditions metallic aluminum which is preferred because of nonur ous affect upon the composition in the obtaining of the features of the invention not excluding its cheapness, and other metals, for instance zinc are satisfactory for the above purpose and will react to release or liberate a as when used witfimfi'a'lumlnate or a mam c 'e' ment which contains no free lime or which contains it in amounts insufficient to obtain proper results according to previous proposals. Such conditions contemplate the maintenance of a minimum temperature during the reaction period to cause generation of the gas to take place, external heat being provided as a catalyst when necessary for this purpose. By this method a product having a proper set that may have a high 50 early strength and that is light, porous and sub stantially free of blooming or eillorescence may be obtained.

I desire it to be understood that while I prefer to make my porous composition by generating or 55 releasing the gas into the cement mixture by the described means by reason of its cheapness and dispersion through the mass before reaction sets in, I may also make a product having the characteristics of the invention by either beating 70 gases or blowing compressed gases into the cement composition.

As a further feature of the invention it has been found that the addition of certain fibres causes the composition to greatly increase E'Bulk,

75 perhaps due to the fibres retarding the escape of gas bubbles and causing the mass to froth, with a high percentage of voids, which are retained when the cement sets. comparatively long fibres appear to produce the most desirable results, possibly because they interlock and give the 5 plastic mixture a tensile strength not possessed by cement compositions containing only small amounts of short fibrous material, and interlock with suflicient strength to entrap the gas bubbles and hold them in suspension during setting of 10 the cement. Long fibres also increase the mechanical strength of the hardened composition andgreatly aid in preventing the material from curling or otherwise deforming during the setting process. 15

Other features of the invention consist in the various details of operation, the combination of steps and the various constructions hereinafter more fully set forth.

Although the novel features which are believed to be characteristic of this invention will be more particularly pointed out in the appended claims, the nature and scope of the invention may be further and better understood by referring to the specific embodiments thereof which are set 25 forth for purposes of illustration in the following description.

In accordance with the preferred manner of carrying out my invention a high aluminate cement or a natural cement of the aforesaid char- 30 acteristics may be mixed with a quantity of metallic aluminum, preferably in the form of finely divided particles or as flakes, and with a mineral, animal or vegetable fibrous material, preferably fiocculent, which may be, for instance, asbestos 85 fibres hair wood fibres cellulose fibres s re e ve e a e res m nera wool co on n ers. A sitaEle temperature, preferably in exc'Tes of about 75 F. may be maintained to cause the aluminum to react with the calcium aluminates 40 of the cement in the presence of water to bring about the release or liberation of hydrogen gas and to form a less basic calcium aluminate. Dependent upon the conditions of application it is preferred that the mix, until used, be maintained 45 at a temperature of about F. or less, in order that substantial gasification of the mass may not occur prematurely. The fibres are preferably of appreciable length so as to interlock to retard the escape of the hydrogen and to impart suificient 5O rigidity to prevent curling or warping when the cement sets. Other light weight aggregates, for instance, granulated cork, may also be included and short fibrous material as aggregates are also not excluded. 55

As a specific example, a quantity of asbestos fibres at least /8 of an inch in length, are nnxe w1 ne aluminum e and the mixture is thoroug y s rre or ea en in water (sufficiently cold to make the temperature of the mix substantially 60 F, or less) so as to disperse the aluminum in the asbestos, a suitable quantity of water being used to produce a plastic mass. TS 5E? mass a desired quantity of high aluminate or natural cement is added. e n s orug y 5 mm nto the mass with the addition of whatever quantity of water may be necessary to maintain the mass in plastic condition. In one instance 3 of a pound of aluminum and 1 pound of asbestos fibres were used with four pounds of cement, and suilicient water included to make a plastic mass. It will be understood, however, that these proportions may be varied over a substantial range.

The plastic composition it will be understood may be formed into any desired shape as in a UUHHHU Ull ll-HUIIUI be in a plastic conditionwhemthepomposition is mold, or may be applied as a facing or coating on a; base material, for Wilbrouswebm; web impregnated and/or coated with asphalt or a base of any ofthe "combinations" or'materials hereinafter referred to. In"a'ny case it is then preferably maintained at a temperature in excess of about 75 F. to cause the desired reaction to occur or continue until the cement sets or the aluminum is exhausted. Thheatednrethe hase may be a hot one if desired. Also the impregnantbrwo'at'ii'ig' B'f'the Basebliiay applied. wh fiitisfprererregthartnetempmsubstantially prevent gasification occurring, which it will be understood is particularly important where the mix is to be used as a coating, it will be obvious that in certain cases as when the mix is made in a mold or is to be poured into one to make a slab of substantial thickness this precaution may, if desired, be omitted.

The gas causes the mass .to froth and to increase greatly in bulk according to the amount of gas generated and the composition of the mix, so that the cement sets, in the form of a light porous mass containing a considerable percentage of voids that are substantially uniformly distributed and in which the interstitial walls are as substantially firm and strong as the surface walls.

The temperature of the material is preferably maintained until the cement has sumciently set or hardened to possess strength to retain its porous structure. Such will be rapid in the case of a high aluminate cement. According to the manner in which the material is manipulated and whether dense surface walls are desired as where the material is to be exposed to the weather, or open surfaces as for acoustical p p ses, the surface walls of the set material may be opened or coalesced as desired.

If the cement has been cast into the form of a large blank it may be cut or sawed into desired shapes such as individual shingles. If the cement composition has been applied as a coating over a base material the same may be cut into the desired lengths or shapes for use.

It is also contemplated that a lining of impregnated and/or coated fibrous material, for instance, felt, may be applied after the cement body has set. For this purpose the felt is impregnated and/or coated with a suitable adhesive which may comprise, for instance, asilicate, a natural or synthetic resin and/or a hot or emulsified bitumen, as asphalt and is pressed with the set cement composition. The adhesive bonds with the cement composition and enters the pores or voids of the set mass to form a firm mechanical anchorage securing the layers together.

This construction is particularly useful in the making of roofing and siding shingles since the composition of the invention can be securely anchored to the base adhesive without the need of an intermediate bond, and can also be bulked to a considerable degree because of its light weight. Moreover, because of the character of anchorage provided and the light weight of the composition it will not slip under the influence of heat when laid to the weather. Such characteristics are not in the prior art as hereinbefore mentioned.

It has also been found that the cement composition of the invention will adhere to a wooden base, such as a wooden shingle. The surface of the shingle is preferably roughened and the plastic composition is applied thereto and treat- LAGIIHHW! ed in the above manner until the cement sets and forms a. light porous coating over the wooden base.

As previously stated the surface of the composition may be coalesced where desired. This may be accomplished for instance by the polished face of a mold by a slight troweling action thereover or by the addition of a liquid veneer comprising cement which may also be a color coating.

It is also contemplated that the cement mass employed for the invention may include coloring material such as dyes or mineral coloring matter providing such materials ar not included in quantities or in a manner that may cause slumping of the mixture. Moreover, where desired, the surface may be embossed at any time before the composition has taken a permanent set by the application of an embossing tool thereto or by casting the material in a mold having a stances it ma e to coat the cement composition with any of the aforesaid adhesive materials without the use of a elt web. In suc cases the adhesive may be applied directly to the hardened composition and a sheet of paper or the like may be applied over the adhesive as to prevent the elements from sticking together during subsequent use, as for example, when they are piled for storage or shipment. The paper may be removed when the shingles are used or may be permitted to remain for the additional reinforcement it provides.

It is obvious that the cement composition of the invention may be used over a base having a granular particle surface such as of brick, slate, shale, etc.,' if desired, to form semi-rigid shingles. It is also obvious that the composition may be applied in any of the foregoing constructions where shingles are to be made, to only the exposed portions thereof. In that case the shingles would be somewhat lighter and the laying thereof in certain assemblies would be facilitated inasmuch as the top edge of the cement composition on one course of shingles could serve as a guide for the butts of the shingles of the next course.

From the foregoing it will be seen that a novel invention has been presented that is particularly useful in the making of roofing and siding materials, and that is possessive of characteristics not heretofore known to the art. Although the invention has been applied to a specific composition and to certain structures by way of example, it is not to be limited thereto as various changes andmodifications will become evident to persons skilled in the art without departing from the features hereinbefore set forth. It is therefore desired that the invention be construed as to include all equivalents and as broadly as the claims taken in conjunction with the prior art may allow. In the specification and claims the term cement substantially free of free lime is intended to mean a cement substantially free of calcium oxide (CaO) and/or calcium hydroxide [Ca(OH)zl before or during hydration.

I claim:

1. In the process of producing a cellular cement composition containing a multiplicity of voids, the improvement which comprises expanding an aqueous high calcium aluminate cement mixture substantially free of free lime, with bubbles of gas and such that said bubbles are dispersed through the wet mass to produce a cellular composition upon setting thereof and permitting the expanded composition to' set and harden,

said cement com-position being characterized by rapidly imparting strength to the walls of the voids during setting and curing of the composition, and by characterizing the hardened composition by substantial freedom from objectionable eiliorescence when exposed to the weather.

2. The process of producing a cellular cement composition suitable for building material, which comprises providing a cement substantially free of free lime but high in calcium aluminates, incorporating with said cement, water, and metal articles adapted to actively generate a gas in reaction with said calcium aluminates and water at temperatures above about 60 F., and reacting said cement and metal particles of the wet cementitious mass at a temperature of the mass in excess of about 75 F., whereby bubbles of gas are generated and dispersed through the wet mass to produce an expanded volume of the composition of cellular character.

3. The process of producing a cellular cement composition suitable for building purposes, which comprises providing a hydraulic cement substantially free of free lime but high in calcium aluminates, incorporating with said cement, water and metal particles adapted to actively generate a gas in reaction with said calcium aluminates and water at temperatures in excess of about 75 F.,

preparing said cementitious mixture as to have a temperature of about 60 F. or less and during the setting reaction of the cement raising the temperature of the mixture to above about 75 F'., to produce active reaction of said cement and metal particles, whereby bubbles of gas are generated and dispersed through the wet mass to produce an expanded composition of cellular character and permitting said composition to harden.

4. The process of producing a cellular cementitious composition, which comprises providing a hydraulic cement substantially free of free lime but high in calcium aluminates, incorporating with said cement, long fiber, water, and metal particles adapted to actively generate a gas in re action with said calcium aluminates and water at temperatures in excess of about 75 F. but not at temperatures of about 60 F. or less, reacting said cement and metal particles of the wet mass at a temperature of the mass in excess of about 75 F:, whereby bubbles of gas are actively generated and dispersed through the wet mass to produce an expanded composition of cellular character.

5. The process of producing a cellular cementitious composition, which comprises providing a hydraulic cement substantially free of free lime but carrying essentially calcium aluminates or calcium alumina ferrites, incorporating with said cement, fiber, water and aluminum particles, and reacting the cement and aluminum particles of the wet mass during the setting reaction of the cement and at a temperature of the mass in excess of about 60 F., whereby to actively generate and disperse bubbles of hydrogen gas of the reaction through the wet mass to produce an expanded composition of cellular character, and permitting the composition to harden.

6. The process of producing a cellular cementitious composition, which comprises providing a hydraulic cement substantially free of free lime but high in calcium aluminates, incorporating with said cement, fiber, water, and metal particles adapted to actively generate a gas in reaction with said calcium aluminates and water at temperatures in excess of about 75 F. but

not at temperatures of about 60 F. or less, said water being suiliciently cold to produce a temperature of the mix of about 60 F. or less, imparting heat to the mixture to raise the temperature of the mix to about 75 F. or greater, to actively react said cement and metal particles of the wet mass, whereby bubbles of gas are generated and dispersed through the wet mass to produce an expanded composition of cellular character, and permitting the expanded composition to harden.

7. The process of producing a cellular cementitious composition, which comprises providing a hydraulic cement substantially free of free lime but high in calcium aluminates, incorporating with said cement, fiber, water, and metal particles adapted to actively generate a gas in reaction with said calcium aluminates and water at temperatures in excess of about 75 F. but not at temperatures of about 60' F. or less, said water being sufllciently cold to retard active reaction of said metal, feeding said mixture into a mold, producing a temperature in the mixture in excess of about 75 F. to cause active reaction of the cement and metal, whereby bubbles of gas are generated and dispersed through the wet mass in the mold to produce an expanded mass of cellular character and maintaining said material in the mold until the cement has set.

8. The process of producing a cellular cementitious composition, which comprises mixing in water, fine aluminum flakes and asbestos fiber comprising fibers at least 4;" in length to disparse the aluminum in the asbestos fiber, said water being sufliciently cold to make the temperature of the mix substantially 60 F. or less, and said water being in sufiicient quantity to produce a plastic mass, adding a cementitious material comprising a hydraulic cement substantially free of free lime but containing calcium aluminates and stirring the cementitious material into the mass with the addition of such water as may be necessary to maintain the mass in plastic condition, raising the temperature of the cementitious composition to about 75 F. or greater, to produce active reaction of said cement and metal particles, whereby bubbles of gas are generated and dispersed through the wet mass to produce an expanded composition of cellular character and permitting said composition to harden.

9. A hardened cellular composition containing a multiplicity of distributed voids comprising the hardened product of an aqueous mixture comprising finely divided metallic aluminum, fibrous material including long fiber, and a calcium aluminate cement substantially free of free lime, said voids resultingfrom bubbles of gas produced during the setting reaction of the cement by reaction of the aluminum therewith and said composition having substantial freedom from objectionable eiilorescence when subjected to weather exposure.

10. A light weight building element comprising the hardened product of an aqueous mixture comprising powdered metallic aluminum, long fibered asbestos, and a calcium aluminate cement substantially free of free lime, said element having a multiplicity of voids resulting from bubbles of gas produced during the setting reaction of the cement by reaction of the metallic aluminum and the calcium aluminate ingredients of the cement, the face of said element being coalesced to present a continuous surface sub- 6. COMPOSITIONS,

COATING OR PLASTIC.

stantially free of voids prevalent within the body thereof.

11. The process of producing a cellular cement composition suitable for building purposes, which comprises providing a high calcium aluminate cement substantially free of free lime, reactable with a metal during the setting reaction of the cement to actively generate a gas but not at temperatures below about 60 F., incorporating with said cement, water and metal particles, reacting said cement and metal particles at a temperature sufllciently high to produce active reaction whereby bubbles of gas are generated and dispersed through the wet mass to produce an expanded volume of the composition of cellular character and hardening the Examiner 

